ABSTRACT
BACKGROUND:The treatment of post-stroke dysphagia with Lipopharyngeal Qibi Formula has achieved good efficacy,and 5-hydroxytryptamine in peripheral serum and neurotransmitters in the nucleus tractus solitarius are closely related to swallowing.Therefore,this study was conducted to explore the modulatory effects of peripheral serum and nucleus tractus solitarius neurotransmitters in swallowing by using modern medical experimental methods such as molecular biology,thereby developing new ideas for the exploration of their mechanisms. OBJECTIVE:To verify the therapeutic effect of Lipopharyngeal Qibi Formula on post-stroke dysphagia and to investigate its mechanism of action. METHODS:Thirty-eight Sprague-Dawley rats were randomly divided into model group(n=14),treatment group(n=14)and sham-operated group(n=10).Animals in the model and treatment groups were modeled by reperfusion after 90 minutes of transient cerebral ischemia by wire bolus method.At 6 hours after modeling,neurological function was scored,and rats with a score of 2 were selected for subsequent experiments.The treatment group was given compound Lipopharyngeal Qibi Formula by gavage starting from the 2nd day after modeling and the remaining two groups were given normal saline by gavage.Changes in body mass,24-hour food and water intake were recorded on days 2,7,14 and 30.The swallowing initiation response time and the number of swallows were detected using a biosignal collector and a tonic transducer on days 14 and 30.After the swallowing test,the ischemic area of the brain in each group was measured by TTC staining.The expression of 5-hydroxytryptamine in the nucleus tractus solitarius of the medulla oblongata was measured by immunohistochemistry.The mRNA and protein expression levels of BCL-2 and BAX in the insula,premotor cortex,cingulate cortex and thalamus of rats in each group were measured by RT-PCR and Western blot,respectively. RESULTS AND CONCLUSION:Compared with the sham-operated group,the body mass,24-hour food intake and water intake were reduced,the swallow initiation response time was prolonged,and the number of swallows was reduced in the treatment and model groups at day 14 of gavage(P＜0.05).Compared with the model group,the body mass,24-hour food intake and water intake of rats were increased in the treatment group at day 30 of gavage(P＜0.05),but were still lower than those in the sham-operated group.Compared with the model group,the swallow initiation reaction time was shortened and the number of swallows increased in the treatment group,but the number of swallows was still significantly lower than that in the sham-operated group(P＜0.05).Cerebral ischemia area was reduced in the treatment group compared with the model group,and the number of 5-hydroxytryptamine-positive cells in the nucleus tractus solitarius of the medulla oblongata was increased in the treatment group compared with the model group,but it was still significantly lower than that in the sham-operated group(P＜0.05).Compared with the model group,the expression of BCL-2 mRNA and protein in the insula,cingulate cortex and thalamus of rats in the treatment group were significantly increased,the expression of BAX mRNA and protein were significantly decreased,and the BCL-2/BAX ratio was significantly increased(P＜0.05).To conclude,the Chinese herbal compound Lipopharyngeal Qibi Formula could improve the number of swallows and swallowing initiation response time,as well as 24-hour food intake,body mass and other swallowing-related indexes in rats with post-stroke dysphagia.The mechanism of action may be achieved by improving the area of cerebral ischemia,inhibiting the apoptosis of neuronal cells in the insula,cingulate cortex and thalamus of rats,thus improving the regulation of the higher centers on the medulla oblongata swallowing center,and regulating the level of 5-hydroxytryptamine in the nucleus tractus solitarius.
ABSTRACT
To study the cognitive effects of diterpene ginkgolides (DG), transient middle cerebral artery occlusion (tMCAO)-induced rats were established. tMCAO-rats induced by suture method were divided into sham operation group, solvent control group, NBP group, DG group. The animal experiments in the present study were performed in accordance with the Ethical Guidelines of the Laboratory Animal Welfare Ethical Committee of Peking Union Medical College (00000646, 00000635). The effects of DG on tMCAO rats were evaluated by neurological severity score, cerebral infarction volume measurement, step-down and Morris water maze test. In the acute tMCAO rat model, 100 mg·kg-1 DG improved the neural score and infarction volume. In the chronic tMCAO rat model, DG 100 mg·kg-1 significantly improved the survival rate of tMCAO-induced rats. The Morris water maze results showed 100 mg·kg-1 DG decreased the latency of tMCAO-induced rats to find the platform, while the effect was weaker than the NBP. However, DG 30 mg·kg-1 did not show a significant effect. In conclusion, DG exerted a therapeutic effect on transient middle cerebral artery occlusion.
ABSTRACT
M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 (S1P₁) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between S1P₁ and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of S1P₁ is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether S1P₁ was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing S1P₁ activity with its functional antagonist, AUY954 (5 mg/kg, p.o.), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing S1P₁ activity with AUY954 administration inhibited M1-polarizatioin-relevant NF-κB activation in post-ischemic brain. Particularly, NF-κB activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through S1P₁ in post-ischemic brain mainly occurred in activated microglia. Suppressing S1P₁ activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that S1P₁ could also influence M2 polarization in post-ischemic brain. Finally, suppressing S1P₁ activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following S1P₁ activation. Overall, these results revealed S1P₁-regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.